Machine for punching venetian blind head bars



July 10, 1962 H. K. LORENTZEN 3,043,178

MACHINE FOR PUNCHING VENETIAN BLIND HEAD BARS Original Filed Sept. 9, 1950 6 Sheets-Sheet l INVENTOR HANS KJOAH/flff/ 'MYZW HIS ATTORNEY July 10, 1962 MACHINE FOR PUNCHING VENETIAN BLIND HEAD BARS Original Filed Sept. 9, 1950 6 Sheets-Sheet 3 INVENTOR llluml 7 IHHHH m II M, umHIIIIIHI.

FIG.8

HANS A. ZOAfA/fZf/V BY 0424/4. ?w. m

HIS ATTORNEY July 10, 1962 H. k. LORENTZEN 3,043,178

CHINE FOR PUNCHING VENETIAN BLIND HEAD BARS Original Filed Sept. 9, 1950 6 Sheets-Sheet 4 8 3 lhlml ulnhllhou NNNNNN o R HA/VS K. LORI-W725 HIS ATTORNEY July 10, 1962 H. K. LORENTZEN 3,043,178

MACHINE FOR PUNCHING VENETIAN BLIND HEAD BARS Original Filed Sept. 9, 1950 s Sheets-Sheet 5 July '10, 1962 H. K. LORENTZEN 3,043,173

MACHINE FOR PUNCHING VENETIAN BLIND HEAD BARS Original Filed Sept. 9, 1950 6 Sheets-Sheet 6 FIG.|3

u l" W FIG.|4

INVENTOR fi/M/S A. l Off/V T Z fN HIS ATTORNEY 3,043,178 IvIACHINE FOR PUNCE'HNG VENETIAN BLIND HEAD BARS Hans K. Lorentzen, Montciair, N .J assignor to Lorentzen Hardware l g. Corp., Hoboken, N.J., a corporation of New York Original application Sept. 9, 1950, Ser. No. 184,055, now Patent No. 2,789,639, dated Apr. 23, 1957. Divided and this application Jan. 23, 1957, Ser. No. 635,824

3 Claims. (Cl. 83467) This invention relates to a machine for punching Venetian blind head bars. The present application is a division of my application S.N. 184,055, filed September 9, 1950, now Patent No. 2,789,639.

In the so-called enclosed metal hea type of Venetian blind, the articulated, superimposed slats of the blind are supported by ladder tapes suspended from a sheet metal channel head bar assembly mounted at the top of the window. Lift cords for raising the blind are reeved through the head bar, and the entire operating mechanism of the blind, including a tilt rod running longitudinally of the head bar and mounting tape rockers to which the upper ends of the ladder tapes are attached, is contained within the head bar. Such a head bar is shown in Nelson United States Patent 2,455,135 and in Nelson United States Patent 2,629,434.

It is customary in Venetian blinds to provide a bottom bar to which the lower ends of the lift cords and ladder tapes are attached, the bottom bar being heavier and more rigid than the slats. Bottom bars may be formed from a sheet metal channel section, such a bottom bar being shown in Nelson United States Patent 2,618,329. In manufacturing such a blind, the head bar channel, the tilt rod, and the bottom bar channel are severed to proper length from stock of indeterminate length, the length of these parts varying according to the Width of the blind and also, to a limited extent, according to local shop practice. The machine disclosed is adapted for the cutting of head bar, bottom bar, and tilt rod stock to proper length and the punching of the bottom wall of the head bar for the passage of the lift cords, tilt cord, and ladder tapes.

In many Venetian blinds designed for an inside mounting (in which the blind is mounted between the window jambs rather than on the face of the wall or window frame), the head bar is slightly shorter than the slats in order to provide the necessary clearance for the installation brackets that support the blind. The bottom bar is usually made slightly longer than the head bar, unless hold-down brackets are being used in conjunction with the bottom bar. It is general shop practice to maintain a constant differential in length between the head bar, the slats, and the bottom bar. It is also common practice to maintain a uniform rout distance (distance from the lift cords to the adjacent ends of the slats) throughout a wide range of blind widths, changing the rout distance only for very narrow or very wide blinds. The length of the tilt rod is determined in part by the rout distance, which can be considered as constant throughout a large range of blind widths.

In computing the required length of a head bar channel, bottom bar channel, and tilt rod, it is necessary to subtract the proper constant differential in order to pro vide for proper clearance and fit of the blind. This problem is not great when manufacturing large numbers of blinds of stock sizes, but becomes much more acute when manufacturing custom blinds, which are tailor-made to individual window measurements.

In the machine shown, a carriage, upon which individual stops for the head bar channel stock, the bottom bar channel stock, and the tilt rod stock are adjustably mounted,

Patented July 10, 1932 is positioned varying distances from the shearing die in accordance with either window width or slat length. Accordingly, by adjusting the individual stops to the proper clearance constant, the carriage may be set directly for producing a blind of any window width or slat length, thus automatically and simultaneously correctly setting all three individual stops.

The stock to be severed is then fed through the die and against the respective stop, after which the die is actuated to sever the proper length. This arrangement provides for a rapid, single, simultaneous setting of all the stops and automatically applies the proper clearance constants to the settings so as to decrease chance of error and aid in quickly and accurately cutting the stock to proper length for manufacture of a particular blind.

This machine is also adapted for the piercing and lancing of the bottom wall of the head bar channel for the passage of the lift and tilt cords and ladder tapes, and to provide upstruck tabs for mounting the fittings in the head bar channel. To this end, adjustable stops are provided on each side of the piercing and lancing dies, these stops being displaceable in the path of a channel fed through the dies so as to locate the channel for punching at the proper distance from its ends so as to properly locate the tilter and cord lock fittings and form the holes for passage of the ladder tapes.

An object of the present invention is to provide an improved machine for quickly and accurately punching Venetian blind head bar channels.

Another object is to provide an improved apparatus for the rapid and accurate punching of Venetian blind head bar channels for the passage of the cords and tapes.

Another object is to provide an improved apparatus for the punching of head bars for blinds having three or more ladder tapes.

A further object of the invention is to generally improve machines of the type disclosed.

Further objects and objects relating to details of structure and economies of manufacture and use will m re definitely appear in the following description.

My invention is clearly defined in the appended claims. In the claims, as well as in the description, parts may at times be identified by specific names for clarity and convenience, but such nomenclature is to be understood as having the broadest meaning consistent with the context and with the concept of my invention. The best mode in which I have contemplated carrying out my invention is illustrated in the accompanying drawings forming part of this specification, in which:

FIG. 1 is a more or less diagrammatic front perspective of the machne. Head her, bottom bar, and tilt rod stock are shown positioned within the dies for cutting.

FIG. 2 is a top plan view of the machine, a portion of the machine having been broken away.

FIG. 3 is an isometric view of a section of head bar channel which the machine is adapted to cut and punch.

FIG. 4 is a view similar to FIG. 3 of a bottom bar channel which the machine is adapted to cut.

FIG. 5 is a view similar to FIG. 3 of a tilt rod the machine is adapted to cut.

FIG. 6 is an isometric view of an inverted head bar channel that has been cut to length and punched for a tWo-ladder-tape blind.

"FIG. 7 is a view similar to FIG. 6 of a head bar channel for a three-ladder-tape blind. 7

'FIG. 8 is a vertical section of the machine taken generally on the line 88 of FIG. 2. Portions of the machine have been omitted and portions broken away, for convenience of illustration.

"FIG. 9 is an enlarged detail section, taken on the line 99 of FIG. 2.

FIG. 10 is a somewhat diagrammatic top plan View,

taken partly in section on the line Iii-16 of PEG. 11 of the portion of the machine for stamping openings for passage of the lift cords and ladder tape, showing the attachments for punching ahead'bar for a three-liftcord blind. 1

FIG. 11 is a front elevation of the portion of the machine shown in FIG. 10. a

FIG. 12 is an isometric view of a slat for a three-liftcord blind.

FIG. 13 is an enlarged front elevation of one of the gauge elements shown in FIGS. and 11, portions of the element being broken away or shown in section for clarity of illustration.

FIG. 14 is a vertical section of the gauge element taken on the line 14-14 of HG. ll.

The head bar, bottom bar, and tilt rod sections which the present machine is adapted to cut and, as regards the head and bottom bars also punch, are shown in FIGS. 3 to 5, respectively. The head bar stock 30 of FIG. 3 is formed of a sheet steel channel of the cross section indicated and is ordinarily supplied in 20 ftplengths. The metal from which the head bar stock 30 is formed is of sufficiently heavy gauge to possess the required strength for a head bar. A generally similar head bar section and complete head bar assembly are shown and described in detail in Nelson United States Patent 2,- 629,434.

The bottom bar stock31 of FIG. 4 is formed of a sheet steel channel of the section indicated. This section likewise is ordinarily supplied in 20 ft. lengths and is severed by the machine of the present invention to form the channel for a bottom bar assembly, the open side and ends of the channel being closed in the assembly by an arched metal Venetian blind slat and end caps. The bottombar stock 31 is severed to desired length and no punching or other forming operation of the channel is required. A bottom bar assembly of this general type is shown and described in detail in Nelson United States Patent 2,618,329.

The tilt rod stock 32, shown in FIG. 5, for incorporation in the head bar assembly is a mild steel rod about A" in diameter. dicated and is usually provided in 20 ft. lengths. The machine of the present invention severs this rod to desired length, and no further forming operations on the rod are required.

A head bar 34 for a two-ladder-tape blind is shown in inverted position in' FIG. 6. This head bar has been cut to proper length from the head bar stock 36 and then punched to receive the lift and tilt cords, ladder.

tapes, and hardware of the blind. The punching of the bottom wall of the head bar includes the forming of pairs of slots 35, 35 for passage of the vertical branches of the ladder tapes, a hole 36 centered between each pair ofslots 35, 35 for passage .of the lift cords, and a slot 37 adjacent each end of the head bar, one slot 37 receiving the depending looped endof the lift cords' and the other 'slot 37 receiving the tilt cord. V

The metal displaced from the wall of the head bar 34 in forming the slots 35, 35 is formed into upstruck tabs which are clenched about the bases of tilt rod cradles'to attach the cradles to the head bar. Similar pairs of tabs at 39, 39 are "struck up from the head bar and 6 except that it is usually somewhat longer than the head bar of a two-ladder tape blind and is provided with a third pair of ladder tape slots 35, 35 usually located substantially midway between the end ladder tape slots. A hole 36 is provided midway between the third pair of slots 35, 35 to receive a third lift cord, if desired.

It has the D-shaped cross secton in- The machine of the present invention also facilitates the stamping of a head bar of this type.

Referring now to FIGS. 1, 2, and 8, the machine of the present invention comprises a cutting die 40 for severing head bar stock 39, bottom bar sock 31, and tilt rod stock 32, and piercing and lancing dies 41 for punching the head bars shown in FIGS. 6 and 7.

The dies 49 and 41 are mounted on a heavy horizontal plate 42 forming a frame for the machine. The plate 42 is supported at a height convenient for the operator of the machine by, a metal stand 44. The metal stand 44 is a box-like sheet metal stand having full sides and rear walls 45 and 46 and a somewhat shorter front wall 47 to leave an opening between the front wall and the base 49 of the stand. A rectangular sheet metal plate 50*, which may be provided with a depending marginal flange 51, forms the top of the stand 44 and receives the plate 42 of the machine. A rectangular sheet metal bottom plate 48 connects the lower ends of the side and rear walls 45, 45 and 46.

The cutting die 40 is of the general type shown in United States Patent 2,644,520. This die has a fixed die member 5-2 that is secured to the bed plate 42 and forming a guide for a movable die member 54. Each of these die members is provided with an opening 55 corresponding with the cross section of the head bar stock 30, an opening 56 corresponding with the cross section of the bottom bar stock 31, and a pair of openings 57, 57 corresponding With the cross section of the tilt rod stock 32, each of these openings being adapted to receive the corresponding stock. Since the tilt rod stock 32 is heavier than the head bar and bottom bar stock and dulls the dies more rapidly, two openings 57 are provided in the cutting die 40 although only one tilt rod is cut for each blind. V

The corresponding openings in the die members are in alignment when the movable die member 54 is in its normal or low position and are out of alignment when the member is raised in the cutting stroke. The movable die member 54 is biased downwardlytoward abutment 48' by springs 53-, 53 and is driven upwardly for the cutting stroke by a downwardly projecting operating rod 59. The rounded upper end 200 of rod 59 is received in a socket at the bottom of the movable die member 54 and clearance is provided between such end 200 of the operating rod 59 and the socket on themovable die member, withthe die member in contact with the upper end of adjustable stop 201 (FIG. 8) on abutment '48 and the push rod retracted downwardly in its rest position, to assurethat the movable die member returns to its normal position in which the respective openings of the fixed and movable die members are in registration. This will be explained more fully in connection with the description of the actuating mechanism for the dies. I

The piercing and lancing dies 41 include a cooperating punch 60 and die block 61 for forming the ladder tape slots 35, 35 (FIG. 6) and lift cord hole 36. These dies also include a cooperating punch 62 and die block 64 for forming the tabs at 39, 39 to receive the tilter or cord lock and for forming the slot 37 to receive the tilt or lift cords.

The die blocks 61 and 64 are mounted on a common die shoe 65 secured to'the plate 42, and the punches 60 and 62 are mounted on acommon punch plate 66. i e

The punch plate 66 is provided with a pair of sleeves 67, 67 (one shown in FIG. 8) which receive a pair of guide posts 68, 68 (see also FIG. 2) located on the die shoe 65 to hold the punches and die blocks in alignment. The punch plate 66 is lowered for thecutting stroke and restored to raised position by a connecting rod 63 connected to the punch plate 66 and projecting downwardly through aligned holes in the punch plate 66, the die shoe 65, the plate 42, and the plate 50 of the stand. A common stripper 58 extends over die blocks 61 and 64 to extract the head bar from the punches 60 and 62 during the return strokes of the punches in the punching operations. This stripper comprises a horizontal plate supported above the die blocks and apertured for passage of the punches.

A rocking lever 69 is mounted on a horizontal pivot 76 supported in a bracket 71 depending from the underside of the plate and secured to the plate 42. Preferably, both the rocking lever 69 and the bracket 71 are formed of spaced parallel plates connected at intervals by webs to avoid unbalanced bending moments on the pins and bearings.

The operating rod 59 of the cutting dies 40 and the connecting rod 63 of the piercing and lancing dies 41 are pivotally connected to the rocking lever 69 by pins 74 and 75, respectively. Preferably, pin 74 is located somewhat closer to the rocking arm pivot than the pin 75, since the travel of the movable die member 54 is much less than the travel of the punches 6i) and 62.

When a cutting or punching operation is to be performed, the rocking lever 69 is rocked in counterclockwise direction (FIG. 8) and then returned, the motion being imparted to it by a crankshaft connecting rod 76 connected to the end of the rocking lever 69 by a pin 77. The crankshaft connecting rod 76 is pivotally mounted on the eccentric of a crankshaft journaled in the lower portion of the bracket 71.

The crankshaft 79 is rotated, under control of the operator, by a flywheel 80 (FIG. 8) mounted for rotation on one end of the crankshaft and constantly driven through a V belt drive 81 by an electric motor 82 which may be of one-third horsepower. The motor, flywheel, crankshaft, rocking lever 69', and associated parts may all be contained within the metal stand 44. The crankshaft 79 and flywheel 80 are connected by a single rotation clutch and brake so arranged that, upon actuating of the clutch, the crankshaft is turned through a single revolution and then stopped. The single rotation clutch is of conventional type used for light presses and will not be described in detail.

The actuating mechanism for the clutch is indicated in FIG. 8. A treadle 84 projects forwardly from the metal stand 44 beneath the front wall 47 (FIG. 1) and is mounted on a horizontal pivot 85. A link 86, pivotally connected to the treadle in front of the pivot 85, extends upwardly outside of the bracket 71 and is pivotally connected to an end of a lever 87 pivotally mounted on the outside of the bracket 71. A link 89, pivotally connected to the other end of the lever 87, extends downwardly to engage one end of a bell crank lever 90 pivotally mounted on the bracket 71. The opposite end of the bell crank lever 96 is connected by a toggle link 9'1 to a clutch-actuating lever 92 pivotally mounted on the bracket 71.

The operation of the treadle 34 and connecting linkage is such that, upon depressing the treadle, the clutch-actuating lever 92 is rotated counterclockwise, as viewed in FIG. 8, so as to actuate the clutch and link the crankshaft 79 with the flywheel 80 for a single rotation of the crankshaft. The crankshaft will be turned for only a single revolution for each depression of the treadle 84', regardless of how long the treadle is held depressed, and the treadle must be returned to fully raised position and depressed a second time after the first revolution of the crankshaft 79 is completed before the clutch will again be actuated to produce a second rotation of the crankshaft. This type of clutch and the control linkages therefor are conventional in the punch press art.

Upon each rotation of the crankshaft 79, the rocking lever 69 is oscillated first counterclockwise and then clockwise, as viewed in FIG. 8, by the crankshaft connecting rod 76. The counterclockwise movement of the rocking lever (as viewed in FIG. 8) acts through the rod '59 to operate the cutting dies 40' in their cutting stroke and also simultaneously acts through the rod 63 to operate the piercing and lancing dies 41 in their cutting stroke. Clockwise return movement of the rocking 6 lever 69 by the connecting rod 76 restores the cutting dies and the piercing and lancing dies to initial position. Since there is a clearance between the movable die member 54- and the operating rod 59, and since the die member 54 is biased toward nonoperated position by springs 53, '53, the die member 54- will return to initial or normal position in contact with stop stud 26 -1 (FIG. 8), even though the Single rotation clutch and brake do not arrest the crankshaft 79 with the rocking lever 69 at the exact end of the clockwise return movement of lever 69.

The head bar stock 30, bottom bar stock 31, and tilt I rod stock 32 are received for cutting on guides located on a right-hand extension of the metal stand 44 (see FIGS. 1, 2, and 9). The head bar stock guide 94 is located at the rear of the extension 95 of the metal stand and serves to support head bar stock in alignment with the opening 55 in the cutting die 40.

The present machine is particularly adapted for the cutting and punching of painted Venetian blind head bars and bottom bars, and to this end the guide 94 is arranged to contact only the interior surface of the head bar stock 30 so as to avoid marring the paint on any visible portion of the head 'bar. This stock guide comprises a relatively rigid, upwardly inclined fin or flange 96, which may have its upper-edge bent back upon itself to form a smoothly rounded upper edge portion adapted to be received within the corner of the head bar stock formed by the intersection of the front and bottom wall (see FIG. 9). The angle and extent of the flange 96 is such that when the upper edge of the rear wall of the head bar is resting against the surface of the flange, the bottom of the head bar will be horizontal and in alignment with the opening 55 (FIG. 8) in the dies. The head bar stock 30 will tend to take this position when placed on the guide 94 due to the fact that the preponderance of the weight of the stock is behind the upper edge portion of the guide and tends to rotate the head.

bar clockwise as viewed in FIG. 9, so as to keep the upper edge of the guide in the corner of the stock 30 and hold the rear edge-bead of the stock against the guide.

If desired, a linear scale 97, graduated in inches, may be attached adjacent the upper edge of the guide 94 to indicate inches from the cutting plane of the cutting dies 40 so as to show the available length of stock remaining after a cut has been completed.

The guide 99 for the bottom bar stock 31 comprises a U-shaped channel 100 mounted on the right-hand extension 95 and provided with rollers 101 projecting upward ly from the channel at intervals, the upper portion of the channel 100 and the rollers 101 being adapted to receive the central portion of the inside of the bottom bar stock 31 and support it in alignment with the opening 56 (FIG. 8) in the cutting dies 40.

The tilt rod guide is comprised of angle fittings 102 secured at intervals on the right-hand extension 95 and each provided with a pair of V-shaped notches 104, 104 at their upper edges for supporting the tilt rod stock 32 in alignment with either of the openings '57, 57 (FIG. 8)

in the cutting die 40.

A left-hand extension 106 of the metal stand 44 is secured to the plate 42 and extends to the left of the machine, as viewed in FIGS. 1 and 2. The left-hand extension is provided at its rear with a track 107 extending from the cutting dies 40. The outer end of the track may project substantially beyond the end or" the extension and be supported by a supplemental support 169.

The track 197 is comprised of a horizontal portion 110 and a vertical, upwardly projecting, rear flange 111. A carriage 1-12 is adapted to run along the track 107 on rollers.

The carriage 112 is provided with a head bar stop generally designated 115, a bottom bar stop 116, and a tilt rod stop 117, these stops being aligned with the openings 55, 56, and 57, 57, respectively (FIG. 8), in the cutting dies 40. Each of these stops is adapted to enstop 14% in FIG. 2.

. 7 V I gage the end of stock passed through the corresponding opening in the cutting dies 40 so as to limit the movement of the stock through the cutting dies. Each of the stops 115, 116, and 117 isadjustable relative to the carriage 112 to vary. the distance of the stock-engaging portion of the stop from the carriage; Linear scales12tl and' 121 (FIG. 2) aresecured to the carriagef112 beside the stops 116 and 117, respectively, and each coacts with an index point on the adjacent stop to indicate the setting of the stop.

The carriage 112'is provided with a latch which is biased upwardly into latching position by a tension spring the forward edge of the track 107 to indicate distance r from the cutting plane of the dies 48*. I

The piercing and lancing dies 41 (see particularly FIGS. 2 and 8) are mounted on the forward portion of the plate 42 and serve to form holes in the'bottom wall of the head barfor passage of the lift cords, tilt cords, and ladder tape and to strike tabs upwardly to receive the fittings located within the head bar, as previously described. The

punch 60 and die block 61 are adapted to form the ladder tape openings 35, (FIG. 6) and the associated lift cord opening 36 in the head bar. I The die block 61 (FIG. 8) is formed to be received within and support the head bar 34 forpunching. A head bar channel gmide 139 (see also FIG. 1), generally similar to the guide 94, is positioned on each side of the die block 61 and serves to support a head bar 34 (which has already been severed to proper length in dies in alignment for sliding along the guide and over: the die block. The head bar channel guides 139, 139 are mounted one on the forward portion of the right-hand extension 95 and one on thee forwardportion of the left-hand extension 1116 (FIGS. 1 and 2). Head bar stops 149, 140 (FIG. 2) are located one on each side of the'die block 61. These stops aid in positioning the head bar 34 for forming the ladder tape and lift cord openings at the end ladder tapes. The arrangement is such that, when the head bar 34- is positioned on one of the channel guides 139 and the end of the head bar is moved over the die block 61 and into engagement with the stop 14% beyond the die block, the head bar will'be properly positionedfor forming one pair of slots 35, 35 and the associated lift cord hole 36. While punching the left-hand group of openings 35, 35, 36 shown in FIGPG,

the head bar is resting on the right-hand guide 139 in FIG. 2 and the left end of the head bar isaligned with the left-hand step 140 in FIG. 2. While punching the right-hand group of openings 35, 35, 36 shown in FIG. 6, the head bar is resting on left-hand guide 139 in FIG. 2 and the end of the head bar is aligned with the'right-hand Foristriking up the tabs at 39,139, and forming the associated slot 37 (FIG. 6), for receiving the tilter or cordlo ck and the tiltcord or lift cords, the die block 64 and punch 62 are provided. These are located just to the-rear of the die block 61 (see FIG. '8). 1. Head bar channel guides 151, 151' (FIG. 2) are located 'on opposite I sides of the die block64, one of these guides being mounted on the right-hand extension 95 and the other on theleft-hand extension 196. These guides are similar to the guides 139, 139 and similarly support the head bar. Four head bar stops 152 (FIGS. 1 and 2) are located two on eachside of the die block 64. These stops are 'turn'slid over the die block 64 from opposite directions and against the center stop 152 which is just beyond the die block, and then punched. However, at times it is desirable to mount both the tilter and the cord lock at the same end of the head bar and, in such instances,

' both stops 152 on the same side of the die block are used.

In stamping the head bar of the three-ladder-tape blind shown in FIGQ7, the slots 35, 35 and associated hole 36, for the central ladder tape and lift cord, are usually located midway between the corresponding slots for the end ladder tapes. The center slots 35, 35 and associated hole 36 are punched by the punch 61) and die block 61 used for forming the corresponding openings for the end ladder tapes. However, in this instance, the head bar stops 1% are not used to locate the head bar for stamping the openings for the central ladder tape. Instead, finger stops 159, 159 (FIG. 1, 2 I 10, 11, 13 and 14) are mounted'formovement along tracks 169,160 extending along' the forward edges of the right-hand and left-hand cables 162, 162 (FIG. 11) passing around pulleys 16 i,

164, located one at the outside endof. each track 160, so as to move together inwardly towards and outwardly away from the die. block 61. Thus, the die block will always remain centered with respect to the finger stops. In addition, an index point 165 mounted on the left-hand finger stop 159 registers with a linear scale 166 located in fixed relation to the left track 16! to indicate the distance of the stop from the center of the die block 61. Each finger stop 159 is provided with a clamping screw 163 for locking the stop against movement along the track 160.

The finger stops 159, 159 may also be located by using one of the blind slats which has already been cut to length and punched. Such a slat 167 is shown in FIG.

' l2 and is provided with a transverse slot 169 for each lift cord. A stationary slat locater 170 isrnounted on the front side of the vertical "plate 145 directly in front of the center of'the die block 61. This slat locater has an upwardly projecting prong 1'71 adapted to be entered within the central slot 169 of the slat 167. Each of the movable finger stops 159, 159 carries a similarconstruction for cooperating with the slat,- i.e., a shelf 172 (FIGS. 10 and 11) provided with an upwardly projecting prong 171' that is adapted to be entered within a center-remote slot 169 of the slat 167; The various ;ways of locating a head bar by use of the finger stops 159, 159 for the punching of the central ladder ta'peand lift cord openings of multitape blinds will be explained hereinafter.

Themachine of the present invention is adapted for themanufacture of both custom blinds and stock blinds. The head bar stop 115 (FIG. 2) is adjustable on the carriage 112 so that the scale 127 of the carriage will indicate directly in inches the actual channel length severed. However, if desired, the stop 115 may be adjusted so that the carriage may be set in accordance with the length of a slat for which the head bar is to be made; and the head bar will be severed to correct length in accordance with .local shop practice. "In inside installa tions (between the window jambs) the head bar is usually up to A inch shorterthan the slats; while in outside installations (on the fronts of the jambs) the head bar may be somewhat longer than the slats.

Custom-made blinds are those blinds which are tailor made to specific window dimensions. Accordingly, in the manufacture of custom blinds, it is particularly advantageous to adjust the head bar stop 115 so that the carriage 112 may be set to the width of the window opening relative to the scale 127, adjustment of the stop serving to compensate for the differential in length between the window opening and the head bar. Accordingly, the head bar stop once having been set in accordance with local shop practice, it is unnecessary to thereafter take into consideration the differential between head bar length and the width of window opening. The carriage may be set directly to Window opening width to produce head bars of the proper length. This construction eliminates a likely source of error in the cutting to length of Venetian blind head bars and makes unnecessary any calculations on the part of the machine operator, thus resulting in a greatly lessened number of bars cut to improper length.

The bottom bar stop 116 and tilt rod stop 117 are also adjustable in accordance with local shop practice so as to automatically produce the proper length differentials between the window width and the lengths of the bottom bar and tilt rod or, which amounts to the same thing, between the head bar length and the lengths of the bottom bar and tilt rod. 'However, if desired, stops 116 and 117 may be adjusted so that the carriage will indicate directly in inches the length of bottom bar and tilt rod severed.

In the manufacture of a head bar for a custom blind, the stops 115, 116, and 117 may be set as above described and the head bar stock 30, bottom bar stock 31, and tilt rod stock 32 positioned on their respective guides 94, 99, and 192. The carriage 112 is then set-to the width of window opening and the head bar stock passed through the opening 55 FIG. 8) in the cutting dies 40 and the treadle 84 depressed to actuate the dies and sever the head bar. In turn, the bottom bar and tilt rod are similarly passed through their respective openings 56 and 57 in the dies 40 and severed to proper length. The bottom bar and tilt rod are then ready for incorporation in the blind, but it is necessary to pierce and lance the severed head bar 34.

The head bar 34 is then transferred to the head bar guide 139 to the rightof the piercing and lancing dies 41. The head bar stops 140, 140 are then set in accordance with the rout distance of the slats and the left-hand end of the head bar passed over the die block 61 and against the left head bar stop 140, the stop being held depressed into the path of the head bar. The treadle 84 is then depressed to form the slots 35, 35 for the left ladder tape and the hole 36 for the left cord'opem'ng, after which the head bar is moved to the left and on to the head bar guide 139 at the left of the dies. The righthand head bar stop 14!) is then depressed into the path of the head bar and the right-hand end of the head bar moved back somewhat, over the die block 61 and against the right-hand end stop 140. The treadle 84 is then depressed to form the right-hand'slots 35, 35 and the right-hand cord opening 36. In punching a cord opening 36 a disc of metal is removed. However, the metal displaced in punching the various slots 35 is preferably formed into tabs which project into the interior of channel 34 and are used to clinch over cradle fittings to secure them in the channel.

After the two groups of openings 35, 35, 36 have been punched, the head bar is removed to the head bar guide 151 at the right of the piercing and lancing dies 41, the left-hand inside head bar stop 152 depressed, and the head bar moved against that stop and punched as .previously described to form the left-hand tabs at 39, 39 and the associated cord opening 37. The head bar is then moved to the left past the die block 64 and onto the left-hand head bar guide 151. Then the right end of the head bar is moved back to the right somewhat, over the die block and against the right inner stop 152. The treadle 84 is depressed and the right-hand tabs at 39, 39 and the associated opening 37 are thereby formed. The head bar 34 is then complete and ready for assembly of the hardware.

In the manufacture of head bars for blinds having three or more ladder tapes, the ladder tape slots and cord opening at inward locations are preferably punched af er punching the like groups of openings toward the end of the head bar and before making the groups of punchings 39, 39, 37 for the tilter and cord lock. The head bar may be located for punching ladder tape and lift cord openings at its center by entering the noses of pivoted fingers 161, 161 (FIGS. 10 and 14) of the finger stop 159, 159 into the lift cord opening 36, 36 at opposite sides of the die block 61, the finger stops being moved apart or together as required by the spacing of such openings 36, 36 on the head bar. Since the finger stops 159, 159 are maintained equally distant from the die block; 61 by the cables 162, 162 (FIG. 11), the head bar is correctly positioned when both pivoted fingers 161, 161 are entered into such respective cord'openings 36, 36.

In blinds having four or more ladder tapes, the ladder tapes are often spaced along the blind at equal intervals. To punch a head bar for this type of blind, the lefthand finger stop 159 may be set with respect to the scale 166 (FIG. 11) to correspond with the selected interval between ladder tapes..Then the pivoted finger 161' of the left-hand stop 159 is successively engaged with the lift cord openings 36 in the head bar, the head bar being fed from right to left between successive operations of the die 41.

Another method of punching the central ladder tape openings of multitape blinds is to position a slat of the blind on the stationary slat locaters 170 (FIGS. 10 and 1 1) with the prong 171 of the locater projecting through the central transverse slot 169 of the slat (FIG. 12). Then one or both finger stops 159, 159 may be located from the slat by engaging projections 171' of the finger stops (FIGS. l4, l0 and 11) with the silt holes 169, the slat resting on shelves 172, 172 of the finger stops 159, 159.

A head bar may also be punched for lift cord and ladder tape openings by marking the center of the group of openings on the bottom wall of the head bar by use of either a linear scale or from a slat that has already been punched for passage of the lift cords. The head bar may then be inserted over the die block 61 and the mark centered over the die block by observation through the window 158 (FIG. 1) in the vertical plate in front of the die block.

If desired, a drawer 43 may be located in the front wall of the stand 44- to receive the metal slugs cut from the head bars by the piercing and lancing dies 41 in forming the holes 36 and 37. The drawer 43 may be removed from time to time as required to empty the slugs.

I claim:

1. A machine for punching channel-shaped sheet metal Venetian blind head bars to provide openings for passage of the central ladder tape or tapes of a blind having tree or more ladder tapes, comprising: punching dies including a die block adapted to receive a head bar, a head bar guide for supporting the head bar in alignment with the die block, a track adjacent the die block and parallel to the head bar guide, support means mounting said die, head bar guide and track in fixed relationship, a projecting prong located adjacent the track opposite the center'of the punching dies and adapted to be received within a rout opening of a slat of the blind, a straight line through said prong and said center of said dies being perpendicular to said guide, a slide mounted for movement along the track, the slide being provided 7 guide.

with a head-bar-engaging portion receivable within an opening previously formed in the head bar: at the end ladder tape, and a projecting prong mounted on the slide opposite the head-bar-engaging portion thereof,

ing punching means for punching the bottom wall of a head bar, a head bar guide for supporting the head bar in alignment With the punching means, a track adjacent the punching means and parallel to the head bar. guide, support means mounting said punching dies, head bar guide and track in fixed relationship, a projecting prong located adjacent the track opposite the center of the punching means and adapted to be received within a rout opening 'of a slat of the blind, 'a straight line through said prong and said center of said punching means being perpendicular to said guide, a slide mounted for movement along the track, the slide being provided with a head-bar-engaging portion receivable Within an opening previously formed in the head bar at the end ladder tape, and a projecting prong mounted on the slide opposite the head bar-engaging portion thereof, said slide-mounted prong being aligned with said first-mentioned prong and being adapted to be received within a second rout opening of the blind slat, a straight line through said prongs being parallel to said guide and a straight line through said. head-bar-engaging portion and said slide-mounted prong being perpendicular to said guide.

3. A machine for punching openings in a channelshaped Venetian blind head bar, comprising: punch means for forming the openings, means to guide the head bar channel for movement longitudinally of itself past the punch means for theforming of the openings at any selected position along the head bar channel, said guide means guiding the head bar in a straight path, means aligned withsaid punch means on a line perpendicular to s'aid' path to support and index a punched Venetian blind slat in definite position with respect to said punch means, indexing means for indexing the head bar channel lengthwise of itself and thereby determining the position along the channel at; which the channel is punched by the punch means, and slat-engaging means aligned with said means for indexing and on a line perpendicular tosaid path, said slat-engaging means being co-operable with the punchings in the slat to establish the setting of said channel-indexing means whereby the punching position along the head bar cannel is selected in accordance with the position of the punchings in the slat.

References (Iited in the file of this patent UNITED STATES PATENTS 346,170 Osgood July 27, 1886 1,424,895 Girard Aug. 8, 1922 1,510,008 Lumb Sept. 30, 1924 1,755,468 Cheshire Apr. 22, 1930 1,825,563 Walts Sept. 29, 1931 2,078,706 Boker Apr. 27, 1937 2,114,259 Trussell Apr. 12, 1938 2,238,680 Cruzan Apr. 15, 1941 2,260,972 Gundlach Oct. 28, 1941 2,373,844 Norsen Apr. 17, 1945 2,431,482 Hutchinson; Nov. 25, 1947 2,445,093 Von Cseh -4 July 13, 1948 2,507,448 McLaughlin May 9, 1950 2,524,344 English Oct. 3, 1950 2,524,583 Yerkes Oct. 3, 1950 2,562,678 Okumura July 31, 1951 2,610,686 Krasberg Sept. 16, 1952 2,816,366 Barlow Dec. 17, 1957 

